Door holder and buffer



June 7, 1949. w. P. BENNETT DOOR HOLDER AND BUFFER Filed 001;. 22, 1946 gamma M WMPBENN E T T Patented June 7, 1949 UNITED PAT IEN T F Fl -CE DOOR'HOLDER. AND BUFFER William-P. Bennett, San'Bernardino, Calif. Application ()ctober;22, 1946, Serial No. 704,896

LClaims. (01. 292-70) This invention pertains to a door holder and bufier but more particularly and specifically to an electro-magnetic door holder and a bufier in the form of a push button type of electric switch.

In the drawings, an embodiment of the invention is illustrated but the invention is not limited to the exact constructions therein appearing-as departures therefrom can be made without departing from the inventive concept.

The primary object of the invention is the provision of a novel-and improved combined door holder and buffer.

Another object of the invention is the provision of an electro-magnetic door holder wherein the electric current to the magnet is automatically turned on upon opening the door and wherein the means controlling the delivery'of current acts as a buffer to the opening movement of the door.

Another and further object of the invention is the provision of an arrangement for holding doors open which arrangementincludes means for auto matically releasing said doors and permitting them to close.

A still further object of the invention isthe provision of a combined door holder andbulfer which is simple and cheapof manufacture, simple of operation and maintenance, highly eflicient and durable in use and which can be quickly and cheaply installed. I

Other objects, advantages, benefits and novel features of construction of the invention appear in and can be understood from the followingdescription when read in the light of the accompanying drawings.

In the drawings:

Fig. l is a side view of the invention. v

Fig. 2 illustrates the invention as used incombination with a door, the door being shown closed.

Fig. 3 is a detail view showing the doorheld in an open position.

Fig. 4 is a schematic illustration of the invention as applied to a plurality of'doors 'whichare normally urged toward a closed position.

Fig. 5 is an illustration of the switch Ill, the switch housing being shown in vertical section.

Describing the invention in detail and referring first to Fig. 1, I is a standard provided with a base 2 intended to be suitably secured to the floor of a room by screws 3 or the like. An electro magnetic coil A is suitably secured to extends across the upper end of the istandardandzout wardly beyond the front of the standardand terminates in a usual and conventional head 5.

Electric current can be supplied to the magnet from any desired'source but for convenience'the 2 current is obtained by plugging into the house'or building current supply thru the medium of-a conventional wall or floor plug. Such a plugJ-B appears in Fig. 2 from which extends a pair of current conductors I and 8.

The conductor l is directly connected to the coil 9 Of the electro magnet while thec'onductor 8 extends to a switch box "IE mounted on the standard I. From the switch or switchbox a conductor I l extends to the coil -9 forcompletin'g the electric circuit when theswitch I0 is closed.

The particular construction of switch utilized is not important. Rather than the construction illustrated in the drawings a 'das-hpot or other type of switch could be substituted.

Describing in detail the switchillustrated Fig. 5 of the drawings it-will be-seen that the push arm B is in the form of an elongated shaft the front end of which is loosely supported'in and guided by a bushing 20 in the front wall of the switch housing while the rear end2l thereof passes loosely through a sleeve 22 which is thread.- edly mounted as at 23 in a bushing 24 in the rear wall ofthe switch housing. The sleeve exterior of the housing is provided witha knurled operating screw or knob 25 While its inner end-within the housing is provided with a-spring'engaging' and retaining cap 26.

Intermediate its length and within the housing the rod or shaft B is provided with an'elongated tubular enlargementZl whichi-ssecured to and movable with the shaft and is composed of a non-current conducting material as for instance plastic. Intermediate its length the enlargement carries a fixed metallic band 28,-a-coil spring 29 surrounds the shaft and ispoitione'd between the inner'end of the enlargementffland the spring retaining cap 26. A -pair' of metallic current conducting fingers 3U and-3| are closely associated with the shaft enlargement 21. The conductor 8 is connected to the finger 3| and the conductor ii to the finger 30, The positions or the fingers 3t and Bi are such that thespringfl normally holds the band 28 out of currentcon-l ducting contact with the fingers "but inward movement of the shaft will carry this band into electrical contact with the fingers and close the circuit across them. I

Outward movement of the shaft is limitedflby abutment of the. shaft enlargement with "the bushing 20 and the degree of resilient tension exerted upon the shaft is adjustable by rotation of the'sleeve 22 in the bushing 24. The spring: 29 acts as a yieldable retarder to the opening movement-of the door. The switch is a normally open switch and is moved to a closed position against spring 29 by the application of pressure upon the switch operating push arm B. This arm extends outwardly from the switch beyond the front of the standard and has its outer end l2 terminating in a vertical plane beyond that occupied by the outer face of the coil head 5.

Referring now to Figs. 2 and 3, C is a swinging door to one side of which is aflixed a metallic plate D which is composed preferably of manganese steel. This plate has a head portion I3 and a base I l and is secured to the door by screws or the like which pass thru suitable openings IS in the base.

In use the electro-magnet is positioned on the floor, closely adjacent to that wall, against which the door is swung when the door is opened. The head of the magnet is positioned in the path of travel of the door and the plate D is positioned so that it will abut the magnet head 5 when the door is moved to an open position. Obviously the magnet can be positioned so that it is abutted by the door at any desired point in the path of travel of the door as it is opened.

In operation, the door is swung open, and its side 16 will first engage the end 12 of the switch push arm B and move the switch to a closed position. This movement is against resilient tension on the arm B and the speed of movement of the door is retarded. The switch arm acts as a buffer. A slightly further opening movement of the door brings the door plate 13 into contact with the magnet head 5 and the door is held in an open position because the switch has been closed, closing the electric circuit and the electromagnet is energized at the time the plate [3 and the magnet head contact. When it is desired to close the door this is accomplished by applying a slight physical force upon the door in a closing direction. This force overcomes the holding power of the magnet and as the door moves away the switch automatically moves to an open position thus breaking the electric circuit but leaving the device in readiness to repeat the described cycle of operation.

Should it be desired the plate l3 can be inset in the door to be flush therewith. The size and shape of the standard, base, electro-magnet is optional and can be Varied at will, as can other features of the invention without departing from the inventive concept.

By the slight modification of the insertion of a master switch in the electric circuit the invenion can be made to serve a very useful purpose in a building where the doors are normally open but are all closed at some specific time. Such a use of the invention is illustrated in Fig. 4 wherein there are a plurality of doors E which are normally urged, in any well known and commonly used manner, toward a closed position. Each of said doors are equipped with a plate D and in conjunction with each door there is an electromagnet A. Plate D and the electro-magnet A are identical to the construction illustrated in Fig. 1 and therefore require no detailed description. Each of the electro-magnets is electrically connected thru its switch It] with a pair of current conductors I! and I 8, the flow of current thru which is under the control of a master switch F.

The mode of operation of this form of the invention is identical to that previously described in respect to opening the door. The difference is in the closing of the doors. When it is desired that the doors close it is necessary only to open the master switch F. This de-energizes the electro-magnets and permits all of the held open doors to close under the influence of the particular means which urge the doors toward a closed position. This arrangement should be of great benefit in the evening for closing all of the doors in a large building as the doors can obviously be of the type which automatically lock. If at any time it is desired to close any particular door while leaving the others open this can be done by exerting the necessary physical force upon the door as has been previously described.

Although the invention is illustrated and described for use with doors, it is to be understood that it can be used and is applicable to other closures where there is a desire or need for holding the closure in an open position. Accordingly, the invention is not to be limited by the drawings but only by the scope of the following claims.

I claim:

1. For use with a door or the like provided at one of its sides with a metallic element, a fixed electro-magnet positioned in the path of travel of said metallic element as the door is moved to an open position, an electric supply circuit for energizing said magnet and including a normally open switch movable to a closed position against resilient tension, and said switch being in the path of travel of said door as the door is moved to an open position and being actuated by said door to close the electric circuit prior to contacting engagement between the door carried metallic element and the electro-magnet.

2. For use with a door or the like provided a at one of its sides with a metallic element, a fixed electro-magnet positioned in t. e path of travel of said metallic element as the door is moved to an open position, a normally open current supply means adapted to energize said magnet,

means operable upon the opening of said door to close said circuit, and said last named means acting to retard the opening of the door and being actuated prior to engagement between the door carried metallic element and the magnet.

3. For use in a building or the like having a plurality of doors which are automatically movable to a closed position and each of which at one of its sides is provided with a metallic element, 9, fixed electro-magnet in the pat of travel of each door carried metallic element when the door is moved to an open position, an electric current suppl circuit including each electromagnet, a normall open movable circuit maker and breaker associa ed in said circuit with each electro-magnet and being in the path of travel of a door and being moved to a circuit closing position by the door as the same is opened and prior to contact between the door carried metallic element and an electro-inagnet, and a master circuit maker and breaker said circuit for simultaneously controlling the delivery of electric current to all of said electro-magnets.

4. For use with a door or the like having at one side thereof a metallic element, a standard provided with a base adap ed to be rigidly secured to a suitable support. an. electro-rcagnet secured to and extending across the end of said standard and having an end adapted to be engaged by the door carried metallic element, an electric current supply circuit [or the magnet, said circuit including a normally open push contact switch movable to a closed position against resilient tension, said switch being carried by said standard and being provided with an outwardly extending switch operating push element,

5 and said push element having its outer end disposed to be contacted by said door prior to contact between said door carried metallic element and the end of said electro-magnet.

5. For use with a door or the like provided at one of its sides with a metallic element, a standard rigidly secured to a suitable support and carrying an electro-magnet, said electromagnet being positioned in the line of movement of said door to an open position and in line with the door carried metallic element, an electric current supply circuit for the electro-magnet including a normally open movable switch movable to a closed position against resistance, means supporting said switch, a movable operating ele- 15 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Dillon Aug. 11, 1914 Number 

